Method of assembling vibratory systems



y 1930. F. PREATOR ET 1,757,335

METHOD OF ASSEMBLING VIBRATORY SYSTEUS Filed March 2. 1929 i i i n I N" N...

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made application or Letters Patent of the.

Patented May 6, 1930 UNITED STATES PATENT OFFICE FREDERICK PREATOR AND DON R, SEELY, 'OF SALT LAKE CITY, UTAH, ASBIGHOBB TO THE 'U'IAlH RADIO PRODUCTS COMPANY, OF SALT LAKE CITY, UTAH, A CORPORA- TION OF ILLINOIS METHOD OF ASSEMBLING VIBRATORY SYSTEMS Application filed March 2, 1929. Serial No. 343,941.

This invention relates to a method for as sembling a vibratory system, and more particularly, the system which forms a part of the dynamic loud s eaker for which we have United States, filed March 2, 1929, Serial No. 343,942.

The principal objects of the invention are: First. To provide a course of procedure by which precision shall be assured in the spacing of the semi-spiders which form the vibratory support for the moving-coil mountin v of a dynamic loud speaker.

econd. A. method which shall be simple,

quick and inexpensive.

In the dynamic loud speaker which forms the subject of the aforementioned application for patent, the moving or so-called voice coil with its appurtenances, is supported in a spider composed of a piece of very thin electro-conductive sheet metal. The spider is made in two parts, preferably symmetrical, each part forming substantially a semi-spider and consisting of a semi-hub and a semi-rim connected by an arm.

When the semi-spiders are assembled to form the spider, they are spaced apart so as to leave a gap between them, this being required, since each part forms a separate conductor for electricity. In its function of supporting the moving coil mounting, it is of the utmost importance that the spacing of the two semi-spiders shall be precise, since the coil must be absolutely concentric with the pole pieces in relation to which the coil vibrates.

To make the semi-spiders separately and attempt to assemble them with the degree of precision required, would be practically impossible, and to attain even a passable degree of precision in the spacing of the semi-spiders, would be a most expensive and laborious procedure.

By means of our improved method, however, the highest degree of precision is as sured at a most nominal expenditure of time and labor.

To this end our method consists in first forming a complete spider, for instance, by stamping the same from a sheet of electroconductive material in the usual manner, which leaves a complete hub and a complete rim. The next step is to cut the hub apart in two places, thus forming the semi-hubs with two gaps between them. The hub is now mounted on the sleeve carrying the coil, and rigidly secured to this sleeve.

Next, the rim is cut apart in two places, preferably at the points of fastening to the pole piece structure, dividing the rim into semi-rims by formingtwo gaps between the semi-rims.

Lastly, the spider with its coil is mounted on the pole piece structure, the semi-rims being clamped thereto and insulated from one another and from the pole piece structure, at the points of clampin The features of this invention for which the protection of Letters Patent of the United States is desired, are collectivel grouped in the claims concluding this speci cation.

In the drawing, which illustrates one instance of carrying this method into practice.

Fig. 1 represents the original spider stamp- Iig. 2, the same with the gaps formed in the hub;

Fig. 3, the same with the coil structure rig idly secured in place within the semi-hub;

Fig. 4, the same after the gaps have been formed in the rim of Fig. 3, thus separating the rim into semi-rims;

Fig. 5, the semi-rims carrying the coil structure, finally secured to the pole piece structure;

Fig. 6, an elevation corresponding to Fig. 5, looking from the left;

Fig. 7, a section on line 7, Fig. 3

Fig. 8, the portion of Fig. 7 enclosed by the broken line 8, drawn to a considerably enlarged scale.

Referring to the drawing, the numeral 20 indicates the Whole spider stamping as originally formed, this being composed of the rim 27 and the hub 32, the rim and the hub being connected to each other b the arms 31. In Fig. 2, portions of the hu 32 are shown cut out, thereby defining the gaps 29 and leaving coil mounting, which may have been accomplished by plaoing the cylindrical paper sleeve 35 into the semi-hubs 324, and Wrapping the layers of paper 36 and 37 around the sleeve 35, so that layers 37 shall lap over the flanges 34 of the semi-hubs 32-4, which, by bein glued or cemented, firmly lock the semihub 1n place on the coil mounting.

In Fig. 4, the gaps 28 have been defined by removing portions of the rim27, thus forming the semi-rims 271.

.In Figs. 5 and 6, the semi-rims are shown clamped to the pole piece structure by means of the screws 42 .threaded in the ring 24, which, together with the pole piece'20l, forms the pole piece structure. Insulating washers 26 are interposed between the spider extremities 301 and 30-2 and the pole piece structure, and the insulating washers 43 between the heads of thescrews42 and" the spider.

Thus, the two semi-spiders 27-2 are precisely spacedapart from each other, as determined by the dimensions of the original spider stamping, and are securely held in place so that this precise spacing shall be permanently maintained.

The ease with which absolutely accurate results are achieved by the use of this method, in assembling the bifurcated spider with the contiguous members, will be apparent to those skilled in the art. Broadly, it makes no difference whether the'hub portion is cut and secured first, or whether it is the rim portion which is so cut and so secured, first.

Taking a vibratory spider having originally. two distinct attaching portions to which contiguous member are'secured, bifurcating first one of said attaching portions so as to roduce independent sections of this particuar attaching portion, then securing these particular independent sections to the respective contiguous member and then proceeding with the bifurcating and securing of the other of the said attaching portions in a similar manner is believed to constitute'a clear and distinct departure from any method of assembling a vibratory system, heretofore practiced.

While we have shown and described a specific embodiment of a structure to which the practice of our invention is applicable, it is are secured, consisting in forming a oneiece spider stamping, removing portions 0 the original spider hub to form the semi-hubs, locking the semi-hubs upon the said coil structure, removing portions of the original spider rim to define semi-rims, and securing the said semi-rims upon said pole piece structure.

2. The method of assembling a vibratory system, ,said system having a vibratory element composed of individual sections, each individual section having a portion attached to a vibrating member and another portion attached to a supporting member; the said method consisting in forming the said individual sections as one piece, cutting apart the first mentioned attaching portion, attaching the said vibrating member, thereafter cutting apart the second mentioned attaching portion and attaching the supporting member.

3. The method of assembling a vibratory system, consisting in. forming a one-piece spider having independent attaching portions, bifurcating one of said attaching portions securing a contiguous member to said bifurcated attaching portion, bifurcating another of said attachlng portions and securing the latter bifurcated attaching portion to another contiguous member.

In testimony whereof we sign our names hereto.

. FREDERICK PREATOR.

DON R. SEELY. 

